THE CHALLENGE: Originally constructed in 1930, the Connecticut Department of Environmental Protection’s (CTDEP) Bridge No. 6321 consisted of a 10 ft.-2in. clear simple span steel stringer and timber plank deck superstructure, on dry-laid abutments and wingwalls. Due to extensive deterioration of the superstructure, the bridge had been closed to vehicular traffic for almost 7 years. As a result, the otherwise 40 vpd traffic volume was detoured approximately 10 miles. A rehabilitated structure was required that improved hydraulic capacity, enhanced site aesthetics, and could be readily constructed with (CTDEP) in-house forces.

THE SOLUTION: The new bridge consisted of an AASHTO HS20 designed, 10ft.-2in. clear simple span glued-laminated timber slab deck on rehabilitated abutments and wingwalls. Primarily because the existing abutments had historic value to the CTDEP, the design was for a rehabilitation rather than a replacement project. The existing bridge seats were raised and abutments strengthened from behind. Upstream wingwalls consisting of stone gabions were added, and downstream dry-laid wingwalls were raised and strengthened. The vehicular bridge rail system was a crash-tested design. The pedestrian bridge rail system included wood composite rails for splinter free protection to pedestrians. A weathering grade metal beam rail was included at all four approaches.

CTDEP Bridge No. 6321 was closed for the construction of the new bridge, which was completed in 2001 after approximately 5 months of construction by CTDEP in-house forces. Final construction material cost was approximately $38,000.

Complete bridge engineering services were provided by Nathan L. Jacobson & Associates, Inc., of Chester, Connecticut. Project management was directed by a principal of the firm specializing in bridge design. Services included survey, design, shop drawing review, and periodic bidding and construction administration and inspection.